Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A parallel beam of light of wavelength $6000 Å$ gets diffracted by a single slit of width $0.3 \mathrm{~mm}$. The angular position of the first minima of diffracted light is
PhysicsWave OpticsKCETKCET 2011
Options:
  • A $2 \times 10^{-3} \mathrm{rad}$
  • B $3 \times 10^{-3} \mathrm{rad}$
  • C $1.8 \times 10^{-3} \mathrm{rad}$
  • D $6 \times 10^{-3} \mathrm{rad}$
Solution:
1199 Upvotes Verified Answer
The correct answer is: $2 \times 10^{-3} \mathrm{rad}$
Given, $\lambda=6000 Å=6000 \times 10^{-10} \mathrm{~m}$ and $n=0.3 \mathrm{~mm}=0.3 \times 10^{-3} \mathrm{~m}$ $0.3 \times 10^{-3} \times \sin \theta=6000 \times 10^{-10}$
$$
\sin \theta=2 \times 10^{-3}
$$
or $\theta=2 \times 10^{-3} \mathrm{rad}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.